Just like there are two common kinds of fuels for traditional cars – petrol and diesel – there are also two types of ‘fuels’ or power for electric vehicles: AC (alternating current) and DC (direct current). The power coming into your home from the grid is only AC.
But what do they mean exactly and how do you know if your car requires AC or DC charging?
Well, let’s set the record straight: EV batteries only store DC power and this is why you’ll see the majority of electronic devices and gadgets having a converter integrated with the plug. In fact, we’re doing this on a daily basis without even realising it – as we plug in our smartphones for charging, the plug is actually converting all the AC power to DC for the sake of charging!
How AC Charging works in EVs
When we talk about electric cars, the AC-DC converter is built into the car. Even though manufacturers and owners alike refer to it as an onboard charger, it really is a converter in reality because it’s what converts the power from AC to DC, so that it can be fed into the car’s battery to turn the wheels.
This happens to be the most commonly used method of EV charging and nearly every charger you’ll find in the market utilises AC power.
How DC Charging works in EVs
As we know, power coming into your home from the grid is always AC. When we wish to distinguish the main difference between AC and DC charging, it’s the actual location where the AC power gets converted to DC, and that’s inside the car.
Now, DC chargers for EVs do not need to go through any conversion as such because the converter is built into the charger – meaning that it’s capable of directly feeding power to your electric car’s battery. Therefore, there’s no “onboard charger” needed as such to convert the current or energy into usable power.
For this reason, DC chargers are a little bigger and heavier, and also charge faster. In fact, they’re a rather exciting breakthrough in the world of EVs.
AC or DC? Which one do I use?
AC charging is the most common method of charging for EVs that have a plug. When you ‘plug’ your vehicle into a charging point, the power will first get converted via the onboard charger and then go to the car’s battery. AC chargers typically require between 3.7 kWh and 43 kWh of power.
It’s an ideal charging method where your car will remain parked for at least 20 minutes or more, so, it’s perfect for parking spots. It’s also a little cheaper to charge your car this way.
If your EV uses or requires a fast charger, then that’s when DC charging comes into play – the power is already converted and ready to be supplied to your battery. This means higher tariffs because the power is being pulled directly from the grid.
This method is perfect for faster charging where you need to charge between those long-distance trips.
